i suspect that the 5 button push button unit to control which combination of Heat or AC or Defrost is operating on a 1983 300D needs replacement. Does anyone have experience with the rebuilt ones and how long they will last? They are about $250 or so and the new ones are near $550 or so.
thanks

I bought a rebuilt unit from these guys last April ($185 + core). So far it works great. I believe it also has a one year warranty:

http://gdl-online.com/price6.html